It is essential, for superior patient care, to provide an accurate means of reporting the results of microbiologic studies of samples collected from the patients and to retreive relevant data as needed. This project provides a computerized system for this purpose. Data from the final reports are temporarily accumulated in a commercial computer and at regular intervals transferred in batches to a computer center where data is processed through error detection and quality control systems. A final report is generated and reviewed and errors are corrected. Individual patient data are regularly summarized as new data are entered and these summary reports are placed in the patient's charts and copies are filed in a central location. Retrieval programs provide data on antibiotic susceptibilities, occurrence of specific species of organisms as to source and numbers, prevalance during specific periods of time, etc.